1. Field of the Invention
The present invention is directed generally to methods of and devices for damaging or destroying a computer hard drive that prevent subsequent retrieval of data from the damaged or destroyed hard drive.
2. Description of the Related Art
Effective data retention and destruction is mandated by a number of regulatory requirements (including, but not limited to, the Gramm-Leach-Bliley Act (“GLBA”) 501 and the Health Insurance Portability and Accountability Act (“HIPAA”)), industry best practices, and expectations (and desires) of consumers with respect to their individual privacy. Various commercially available methods and devices intended to address these requirements offer only varying degrees of effectiveness. These methods include software based methods (e.g., using operating system commands or secure file deletion software to delete data), electromagnetic methods (e.g., degaussing), and mechanical methods (e.g., crushing, or drilling).
With respect to software based methods, using conventional operating system commands to delete files from a hard drive is not an effective way to remove data from the hard drive because most operating systems do not actually delete bit patterns physically stored on the drive. Instead, most operating systems simply remove a file system pointer to the data. After this pointer has been removed from the file system, the drive sectors storing the data are available for reuse by other files. When a drive sector is reused, the data previously stored in the drive sector is overwritten with new data. However, many operating systems leave behind “ghost pointers” that may be used (by file recovery or un-deletion software) to retrieve data the user thought was permanently deleted. Even if “ghost pointers” are not available, there is no guarantee that the drive sector containing the data will be reused. Further, even if the drive sector containing the data is reused, the magnetic alignments of bits (written by the drive's write head) do not necessarily guarantee the magnetic fields of all electrons are aligned in the same direction as others representing the same bit of data. Therefore, equipment capable of reading magnetic fields on the drive platters in sufficient detail may be used to recover enough of the original bits, which (when used in combination with statistical reconstruction algorithms) may be used to reconstruct a reduced resolution version of the original data stream.
Secure file deletion software is not completely effective for the same reasons described above. Some secure file deletion software attempts to make data recovery impossible by repeatedly overwriting the data stored on a hard drive. While statistical reconstruction after multiple random and patterned overwrites is more involved and less reliable than a reconstruction created after a single overwrite by another file, such statistical reconstruction remains within the realm of theoretical possibility.
Electromagnetic methods have also proven ineffective. Drive degaussing is not completely effective for the same reasons secure deletion software is not completely effective. As a matter of fact, the high intensity magnetic field aligns most of the magnetic fields on the drive platters in a single direction but may not align all magnetic fields on the drive platters in that direction. Magnetic fields that are not realigned could allow the statistical reconstruction described above to be performed. However, degaussing does have the added advantage of potentially damaging the electronics of the hard drive thereby rendering the hard drive inoperable. Conversely, this could be considered a disadvantage because to determine whether the degaussing operation was effective, one would have to attach undamaged electronics to the drive platters. Nevertheless, such damage does not prevent removal of the drive platters, which may be examined independently as described above. In addition, newer hard drives have greatly improved magnetic shielding designed to protect from interference during normal operation which reduces the overall effectiveness of degaussing.
Many conventionally used mechanical methods, such as drive crushing or drilling, are also not completely effective. While the process generally renders the drive inoperable (e.g., prevents the drive platters from spinning within the original drive assembly), the drive platters, which still contain an overwhelming majority of the original data, may be removed from the original drive assembly. Much of the original data can be retrieved from the drive platters by a device capable of high resolution analysis of the magnetic properties of the drive platters.
Services offering hard drive destruction that reduce the hard drive to small particles do exist; however, they are inconsistent in the size of the particles produced from the hard drive. Many of the particles produced are large enough that individual analysis of the magnetic fields on the fragments is still possible (similar to reconstructing a shredded paper document). In addition, many of the services of this nature require specialized equipment. In some case, the specialized equipment is moved to the location of the hard drive, which can be expensive. Alternatively, end of life hard drives may be shipped to the specialized equipment (e.g., at a central location), which requires the owner of the hard drive to relinquish control of the hard drive to a third party for transport. Obviously, this is not without some risks that the hard drive will be misappropriated or lost during transport.
Therefore, a need exists for methods of destroying a hard drive that ensure data stored on the hard drive cannot be retrieved that also allows the owner of the hard drive to maintain possession and/or control of the hard drive at all times. A portable device configured to destroy a hard drive such that its data could not be recovered is also desirable. It would be beneficial if such a device could be configured to operate in a conventional office, mobile, and/or retail environments (e.g., be powered by a standard electrical service, operated quietly, operated safely, and the like). The present application provides these and other advantages as will be apparent from the following detailed description and accompanying figures.